Manchester United legend Paul Scholes stated he is "genuinely scared" for the club's future, and fears they could vanish into the wilderness the same way archrivals Liverpool did in the 1990s.
The 39-year-old urged the Red Devils to sign five "proper" players to avoid any critical situation, and also revealed his choice of those five - Xabi Alonso, Sami Khedira, Raphael Varane, Angel Di Maria and Mats Hummels.
"I am scared for United. Genuinely scared they could go into the wilderness in the same way Liverpool did in the 1990s," The Independent quoted Scholes.
"What do they need? Five players. Five proper players who can hit the ground running and turn round a situation that looks desperate. Let me be clear: I am sick of having to criticise the club to which I gave my life as a footballer. But United need to arrest their decline.
"In those years under Alex Ferguson, when trophy followed trophy, this sort of mediocrity was unthinkable. But it is happening."
The 20-time Premier League champions finished seventh in the league last season. Following their poor campaign, the club's then manager David Moyes was sacked in April, after just 10 months in charge.
United started the new season under new boss Louis van Gaal at the weekend, losing 2-1 to Swansea City at Old Trafford. The Dutchman has since strengthened the squad, with the signing of Sporting Lisbon's versatile defender Marcos Rojo.
However, Scholes believes the club needs to invest more money on signings, before the close of transfer window on 1 September.
Scholes, who played for United for his entire career and won 11 Premier League titles, also revealed that he urged the club to bring in Barcelona's Cesc Fabregas (now at Chelsea) and Bayern's Toni Kroos (now at Real Madrid) this summer.
"In the few weeks at the end of last season when I was part of Ryan Giggs' coaching team at Manchester United, I was asked my opinion on whether the club should sign Cesc Fabregas or Toni Kroos this summer.
"I thought there was only one response to that difficult choice between two great players. I said United should sign them both. I do not know what happened to the Kroos and Fabregas deals over the summer. Perhaps Louis van Gaal did not fancy either of them."
The Red Devils will play Sunderland at the Stadium of Light on Sunday.